package com.cloud.utils;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class SpringContextHolder implements ApplicationContextAware {
 
	private static ApplicationContext applicationContext;
 
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
		SpringContextHolder.applicationContext = applicationContext;
	}
 
	public static ApplicationContext getApplicationContext() {
		assertApplicationContext();
		return applicationContext;
	}
 
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String beanName) {
		assertApplicationContext();
		return (T) applicationContext.getBean(beanName);
	}
 
	public static <T> T getBean(Class<T> requiredType) {
		assertApplicationContext();
		return applicationContext.getBean(requiredType);
	}
 
	private static void assertApplicationContext() {
		if (SpringContextHolder.applicationContext == null) {
			throw new RuntimeException("applicaitonContext属性为null,请检查是否注入了SpringContextHolder!");
		}
	}
}
